Technical Field
The present invention relates to characterizing layers of an object, and more particularly to systems and methods for generating cross-sectional composition and structural information using a scanning electron microscope (SEM).
Description of the Related Art
A scanning electron microscope (SEM) produces images of a sample or specimen by scanning with a focused beam of electrons. The electrons interact with atoms in the sample and produce signals that include information about a sample's surface topography and composition. An electron beam is scanned, and its position is combined with a detected signal to produce an image. SEM can achieve resolutions of better than 1 nanometer.
The electron beam may have an energy ranging from 0.2 keV to 40 keV and is focused by one or more condenser lenses. The beam scans in a raster pattern over an area of a sample. SEM can provide several items of data at each pixel. One example includes energy-dispersive X-ray spectroscopy (EDS). An EDS detector may be employed for elemental analysis to analyze an intensity and spectrum of electron-induced luminescence in specimens. The spectra signals can be color coded, so that differences in the distribution of the various components of the specimen can be seen clearly and compared.
In many applications, specimens are cross-sectioned to determine constituent structures and materials. In many instances, the specimens to be cross-sectioned are too fragile or too small to deconstruct or cross-section, or the specimens need to be preserved for other analyses where non-destructive testing is needed.